Fargo-Moorhead Area Diversion Project
Transcription
Fargo-Moorhead Area Diversion Project
Fargo-Moorhead Area Diversion Project Aaron Snyder USACE Planner and Project Manager, PMP Chief, Project Management Branch Mark Brodshaug Cass County Joint Water Resource District, Chairman Presentation to: Joint North Dakota Water Convention and Irrigation Workshop December 4, 2014 Presentation Outline Flood History & Project Need Flood Insurance Federally Authorized Project Project Operations Mitigation Efforts Funding & MN DNR EIS Update Questions 2 Flood History & Project Need 3 Red River Basin Total Drainage Area: 45,000 square miles North Dakota Fargo, Moorhead, ND MN Minnesota Q 100 year = 34,700 cfs South Q 500 year = 61,700 cfs Dakota 4 Q max 2009 = 29,500 cfs Water Everywhere West of Hjemkomst Center Moorhead, MN & Fargo, ND Transportation Challenges Interstate 29 Closed April 10. Reopened April 15, 2011. Detour added = 22.8 miles Red River of the North at Fargo, North Dakota Maximum Daily Flow Rate (cubic-feet per second) 70,000 60,000 ● Flood flow frequency and magnitude since 1900 shows transitions from dry to wetcycles. 50,000 ● 16 flood have exceeded the "Major Flood Stage" since 1900. 40,000 ● 8 of the 16 "major" floods have occurred since 2000 through 2014. 30,000 20,000 Approximate Major Flood Stage 10,000 0 Source: USGS river flow data from USGS Station 05054000 500-Year Flood Event 100-Year Flood Event The 2009 flood is the largest flood on record and equates to a 50-Year Flood Event. Greater than 100-Year Protection is Needed Bigger floods have already been experience in Minot and Grand Forks, North Dakota Several 1,000-year flood events have occurred across the region in the last few years Red River Basin Commission recommends 500-year protection for large metro areas like FargoMoorhead Only Winnipeg meets the RRBC guidelines for flood protection for cities in the Red River Basin 8 Diversion Projects Have Proven Success in the RRB Diversion Project in Winnipeg in place since 1969 – Was recently expanded from 90-year flood protection to 700-year flood protection Has operated more than 20 times since its completion The prevented $32 billion in flood damages Sheyenne Diversion continues to succeed in West Fargo, North Dakota 9 Flood Insurance 10 Ever Changing Floodplain Risk Pre-2015 FEMA Floodplain 38.5 Feet River Gage (29,300 cfs) 475 Impacted Structures 19,700 Acres Impacted 2015 FEMA Floodplain 39.4 Feet River Gage (29,300 cfs) Approx. 2,300 Impacted Structures 27,600 Acres Impacted Future USACE Floodplain 41.1 River Gage (34,700 cfs) Approx. 19,400 Impacted Structures 36,430 Acres Impacted Flooding Without The Diversion Blue = Existing 100-year Floodplain (USACE) Flooding With The Diversion Blue = With Project 100-year Floodplain (USACE) Federally Authorized Project 14 Federal Feasibility Study Multiple Alternatives Considered • Non-structural • Levees/floodwalls • Upper basin storage • Retention/controlled field runoff • Diversion channels • Combinations - Diversions and Levees - Various levels considered - 10,000 to 45,000 cfs capacity diversions - Up to 1-percent chance levees • Levees alone unable to achieve certifiable 1% risk reduction 15 Why Not Levees? • 100-year certification not feasible • 50-year level (2009 flood) - $900 million cost • No high ground on North Dakota side • Once levees are exceeded, entire community floods • Not as robust/reliable as diversion • Levee projects also have impacts 16 Why Not Distributed Storage/Retention? The Diversion Authority supports the development of distributed storage The Diversion Authority has committed $25 million to develop upstream retention projects Distributed storage cannot provide the level of protection of the Diversion (~7’ reduction of the 100-year flood stage). The staging area is the most effective and efficient retention, which is necessary to mitigate downstream impacts. 17 Initial Diversion Plan’s Downstream Impacts • Impacts in excess of 2-feet • Downstream impacts would have reached to Canada • Impacts on an estimated 4,500 structures downstream of project based on pre-feasibility study information • Downstream impacts have been nearly eliminated by implementing the staging area; the most effective and efficient upstream storage 18 FM Area Diversion Project Federally Authorized Project 1,600 ft wide Diversion Channel in ND with 150,000 acre-feet of Upstream Staging Outlet near Georgetown, MN Inlet north of Oxbow, ND Provides 1-percent (100-year) Risk Reduction Extreme Events are FloodFightable Diversion Project Receives Federal Authorization President Obama signed the Water Resources Reform and Development Act (WRRDA) in June 2014 WRRDA authorized construction to move forward on the FargoMoorhead Area Diversion Project. WRRDA authorized $846 Million in federal funds for the Project Diversion was 1 of 26 water projects authorized 20 Federally Authorized Project Provides risk reduction: to the greatest amount of infrastructure for the greatest number of people from multiple river systems • • • • • • Red River Wild Rice River Sheyenne River Maple River Rush River Lower Rush River Harwood 21 Authorized Project Makes Sense 1 in 5 of all North Dakotans will benefit from flood risk reduction $14 Billion = Property Value Receiving Flood Risk Reduction Benefits $4.3 Billion = Wages in the F-M Metro Area $10 Billion = Annual F-M Gross Domestic Product $222 Million = Annual Income & Sales Taxes Generated for North Dakota from F-M Metro $90 Million = Annual Income & Sales Taxes Generated for Minnesota from F-M Metro *Data from the Greater Fargo-Moorhead EDC Improvements to the Project Reduced the impacted residential structures from 4,500 downstream to just 150 upstream of the Project Included a ring levee for Oxbow-Hickson-Bakke, which prevented a community-wide buyout of 196 homes Moved southern alignment of the Diversion north by one mile. – Lessened residential structure impacts and impacts to Richland and Wilkin counties to just a handful of residences Added gates to the Diversion Inlet to allow more flow through town and to better control and minimize upstream impacts. – Diminished potential for summer flooding upstream and damaging standing crops Increased levee heights within Fargo-Moorhead – Lowered the frequency of Diversion use to only operate in flood events greater than a 10-year flood (35 feet at Fargo gage) – Reduced size and duration of the Staging Area Diversion Channel Cross Section Total Width = 1,600 feet 24 Typical County Bridge Aesthetics Conceptual Maple River Aqueduct Structure Illustration In-Town Levees Key Aspect of Diversion Project Over 700 home buyouts metro-wide to date 35 foot Mitigation Measures • • • • • • Existing Levee Certification (5) El Zagal Area Protection Mickelson Area Protection 2nd St./Downtown Protection Belmont Area Protection Individual Property Mitigation/Acquisitions • Transportation mitigation measures (rural). Diversion Project Operations 28 10-Year Flood Operation No Project Operation Under 10-Year Flood Event 10-Year Flood Event = 35’ at Fargo Gage Project would not have operated during a historic summer events (1975, 2005, 2007, 2009) 29 Staging (“Retention”) Area (100-year Event) Defined area Ability to mitigate for impacts Impacts to approximately 60 residences, with ring levees around Oxbow-BakkeHickson and Comstock Virtually eliminated all downstream impacts 30 Mitigation Efforts 31 Ongoing Mitigation Efforts Residential Mitigation – Residence and Farmstead Mitigation • Impacts on residences and farmsteads >1’ require federal mitigation (approximately 80 homes) • Additional mitigation <1’ on a case by case basis – Hardship Acquisitions • 6 homes have been purchased at the request of their owners due to hardships (2 additional have been approved for acquisition) – Early Acquisitions • Several farmland owners have approached the Diversion Authority with an interest in selling their land • The Diversion Authority has purchased 2,000 acres of farmland from willing sellers who approached the Diversion Authority 32 Ongoing Mitigation Efforts Cemetery Mitigation – Corps of Engineers has released a 185-page report detailing the cemeteries in the region, their current flood threats, and what impacts may be from the Diversion Project along with potential mitigation options. Agricultural Mitigation – Flowage Easements • A flowage easement is a one-time payment made to provide the legal ability to inundate property as part of the operation of the Project – Replacement Income (Crop Insurance) • NDSU’s Agribusiness Department has been contracted to develop a plan to mitigate the impact on farmland 33 OHB Ring Levee Construction began in June, 2014 Provides 196 properties with 500-year flood protection Removes real estate “limbo” status for residents Protects the tax base of the Kindred School District 34 OHB Ring Levee Project (Sept 26, 2014) REPLACEMENT LOTS AND DEVELOPMENT RING LEVEE 35 Funding & MN DNR EIS Update 36 Current Funding Philosophy Total Project Costs Federal : 45% (capped at $800M) Non-Federal: 55% (balance of Project Costs) North Dakota: 90% State: 50% 37 Local: 50% Minnesota: 10% Funding Update Local Funding Voters have approved two dedicated sales tax measures for the Diversion Sales tax projections estimate collections to total $700 Million over the life of the taxes ND State Funding State legislature has appropriated $175M with legislative intent to give another $275M Federal Funding 38 Authorization set the stage for this effort to begin Minnesota Environmental Impact State & Funding Update The DNR must produce an Environmental Impact Statement (EIS) for the Project as required by Minnesota law – EIS started February 20, 2014 – Draft EIS publication estimated April 2015 EIS examining five (5) Alternatives, including the Federal Project and Two No Action Alternatives Intent for Minnesota to cover 10% of all non-federal Project costs, roughly 5.5% of total Project costs Minnesota cost share could be requested from the MN Legislature during the 2016 legislative session at the earliest 39 www.fmdiversion.com 40 www.fmdiversion.com Questions?
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